The invention relates to a so-called container sharpener having a pencil or core sharpener and a cover housing that surrounds the sharpener and catches shavings, the housing including a floor part and a closing hood that can be detachably secured thereto.
In container sharpeners of this type, the detachable hood serves to catch shavings. It prevents undesired accumulation in the surrounding area during sharpening.
To promote efficient production, it is known to manufacture the cover housing, which comprises a floor piece and a detachably-secured hood, as a separate component and to secure a separately-manufactured sharpener to the floor of the cover housing as a conventional, inexpensive practice in mass production. This sharpener typically includes only a sharpener housing, which comprises plastic or metal, e.g., aluminum, and surrounds a guide channel having a conical tip end, as well as a cutting blade that is screwed to the sharpener housing, or extrusion-coated in one piece with the housing with the use of the sharpener-housing material. The sharpener is a commonplace, mass-produced item. Container sharpeners having a separate cover housing comprising a floor part and hood and a pencil or core sharpener secured therein are known from DE 27 45 600 A1, in which case the sharpener is secured to the floor part of the cover housing through a clamp connection.
Primarily for reasons of aesthetics, cover housings for such sharpener units have a complicated design. They are often augmented with additional functional components whose technical or design-related construction is tailored to specific customer preferences, and increases the costs of producing the cover-housing parts, particularly the hood. Because customer preferences in terms of the technical and design-related construction of the sharpener can vary greatly, the piece numbers demanded by the market are too small to justify a high production outlay for the cover housing and its technical and design-related construction.
It is an object of the invention to solve this problem using technical means that lay the foundation for efficient mass production of the cover housing. This object is accomplished by at least one of the parts of the cover housing being provided with notched projections, which project into the housing, for securing the sharpener through clamping or snapping, wherein the notched projections are positioned and configured so that both a small-format sharpener due to pressure on the outside walls of its housing from the outside inward, and a large-format sharpener due to expansion pressure on the wall regions of its housing from the inside outward can be secured between the notched projections. With this solution, the notched projections can selectively be pressed inward from the outside due to pressure on the outside walls for the clamping or snap connection of a small-format sharpener, or they can be expanded outward due to expansion pressure against wall regions of the housing, to accommodate a large-format sharpener. Of course, the exertion of the expansion force stipulates that the affected wall regions be externally accessible to the notched projections.
With the invention, it is no longer necessary to produce a separate cover housing for sharpeners of different formats. If the connection of the sharpener to the cover housing is effected by clamps or snaps, it is a type of connection described in detail in Carl-Otto Bauer""s xe2x80x9cHandbuch der Verbindungstechnik [Handbook on Connection Techniques,xe2x80x9d Carl Hanser Verlag [publisher], Munich, Vienna, 1991, pp. 269 et seq. and 295 et seq. The ability of the cover housing to secure sharpeners of different formats in clamp or snap connections, and position their guide channel for the pencil or core end precisely opposite the throughgoing opening of the cover housing, forms the basis for a viable piece-number production of cover housings or their components.
Another object of the invention capitalizes on the fact that the sharpener housings of large-format sharpeners, which are usually made from injected plastic, have thin walls. According to the invention, this injection-molding technology prevents sink marks and also saves material. As a result, the outside of the housing floor of large-format sharpeners in particular is cleaved, with the side walls of the sharpener housing freely projecting downward from the floor. This gives the sharpener, which is positioned on a base, a compact design, and by nature offers the option of accessing the downward-projecting side walls of the sharpener housing through the notched projections. In this instance, the invention employs conditions in large-format, mass-produced sharpeners that therefore need not be individually adapted for their intended use inside a cover housing in accordance with the invention.
Another embodiment of the invention has notched projections forming a U-shaped clamping rib. This embodiment allows a simple, yet especially effective method of attaining a precise positioning of the respective sharpener inside the cover housing using a clamping technique.
Another embodiment of the invention relates to a particulary effective embodiment of the clamp or snap connection in the clamping of a large-format sharpener. The peripheral wall intended for securing the closing hood of the cover housing, or parts of such a peripheral wall of the floor part, together with the notched projections projecting upward from the floor part, form a clamping groove. The side walls projecting downward beyond the housing floor of a large-format sharpener can be clamped particularly effectively between the side walls of this groove. This improves the reliable positioning of the position-fixed, large-format sharpener on the bottom part of the cover housing. Consequently, during sharpening, the sharpening forces acting on the sharpener or the sharpener housing are absorbed especially well. The sharpener will not loosen inside the cover housing, even with the occurrence of heavy vibrations.